WASHINGTON — Flu vaccination rates have remained steady overall, but rates continue to vary between age groups and among states, according to data from a Centers for Disease Control and Prevention study published Thursday.

Leaders from the National Foundation for Infectious Diseases, CDC, American Pharmacists Association, American Medical Association and others gathered at the National Press Club in Washington Thursday morning, where public health officials and medical experts, including the Department of Health and Human Services' assistant secretary for health, Howard Koh, received flu vaccinations.

The CDC study, announced to coincide with the event, showed that an estimated 128 million people, or 42% of the U.S. population, received flu vaccinations during the 2011-2012 season. Vaccination rates among children ages 6 months to 17 years remained steady, at 52%, with rates among those ages 6 to 23 months increasing to 75%, a 6% rise over the 2010-2011 season. But coverage of children also decreased with age: Among those ages 13 to 17 years, the rate remained at 34%. Meanwhile, adults ages 65 years and older showed rates of 65%, but that represented a decline from 74% in 2008-2009. Among pregnant women, rates increased from 30% in 2008-2009 to 47% in 2011-2012, and vaccination rates among children were comparable across ethnic groups, but disparities remained in the adult populations. The CDC reported noted that coverage remained below the goal rate of 80% for those ages 6 months to 65 years and 90% for those ages 65 years and older.

"The past three years have demonstrated that influenza is predictably unpredictable," Koh said. "When it comes to flu, we can't look to the past to predict the future. Stay healthy — get vaccinated."

APhA chief strategy officer Mitchel Rothholz lauded the role pharmacists had played in vaccination efforts. Pharmacists in all 50 states, the District of Columbia and Puerto Rico can administer influenza vaccines.

"Pharmacists have been offering flu vaccines for nearly two decades, but the 2009 pandemic prompted greater collaboration throughout the immunization neighborhood, resulting in sustained public health gains," Rothholz said. "Pharmacists and pharmacists are playing a greater role within the immunization neighborhood in making vaccines and vaccine information more accessible to all community residents."

More than 85 million influenza vaccine doses were distributed as of Sept. 14, and manufacturers project that 135 million will be distributed during the season in pharmacies and other retail stores, doctor's offices, public health clinics and other venues, according to the NFID.